I am curious about how to handle picking a girl up in a situation where just being there makes you undesirable. I mean situations where it is impossible to have believable excuse for being there.

These examples don't apply to me specifically, but I am hoping to make it a bit more general, so I can get more ideas.

A girl who happens to work in a porn shop, but being in the porn shop puts you in the same box initially as the tons of creepy guys she probably has to deal with all day.

A booth girl at some uncool convention, which lobs you immediately with all the other uncool guests.

A stripper, hostess, etc. Someone who's job is to be attractive so you spend money. You want to be there, but don't want to be a "client"

A girl who works in a casino, but doesn't like guys who gamble.

Basically anyone who works or frequents a place, in which being in the place may immediately disqualify you, and you have no other excuse to be there.

I guess one could wait for them to get off work, and try to approach in another setting... but that is kind of creepy and stalkerish. So I am wondering if anyone has advice for these sort of situations.